How to choose the right material for cosmetic packaging

Before involved in plastic industry, I always tried to avoid using the plastic products, My daily use of the cups were made of glass, ceramic or stainless steel, as I always felt plastic products were unsafe, after I contact sanleplastics-plastic industry,

At the bottom of plastic bottles, most of them have a recycling symbol, What do these Numbers represent, and how do you use them to determine what plastics are made of and how to use them? Here is a brief explanation:

Many people outside China always think that China doesn't have the ability to produce good products, I have seen a question on Quora which goes “why doesn’t China have the ability to manufacture high-quality products”, this question has already been proved is worry by the answers that foreigners offered.

Do you know how many types of plastic materials out there?